1. Field of the Invention
This invention relates to windshield wiper blade assemblies and, more particularly, to structure for preventing noise development between interconnected elements on a windshield wiper blade assembly.
2. Description of the Prior Art
A typical windshield wiper blade assembly consists of a wiper arm with a reciprocating drive, a primary yoke pivotally connected to the wiper arm, at least one secondary yoke connected to the primary yoke for movement relative thereto, and a wiper element with a flexor connected to the secondary yoke. At the points of connection between the primary and secondary yokes and between the yokes and the wiper blade flexor, there is metal-to-metal contact. As the wiper blade assembly is operated and the wiper element is conformed to a windshield surface, relative movement occurs between the yokes and between the yokes and flexor resulting in the production of an annoying rattling noise.
One partial solution to the above problem is taught in U.S. Pat. No. 3,629,898 to Plisky. In Plisky, dimples are formed in the primary yoke and define contact points for engagement with the associated secondary yokes. While Plisky's structure represented a substantial improvement over the prior art structures, there is still metal-to-metal contact at the connection between the primary and secondary yokes, even though the area of contact is substantially reduced. Further, Plisky does not address the problem of rattling between the secondary yokes and the blade flexor, at the connections therebetween.
U.S. Pat. No. 3,772,730, to Plisky, also discloses a structure that reduces contact area between connected yokes. Plisky provides a recess on one of the yokes to accept a portion of another, articulated yoke. While Plisky also discloses an effective structure for connecting windshield wiper elements, Plisky also has some metal-to-metal contact and does not disclose any structure for preventing rattling between the secondary yokes and the wiper blade flexor.